diff options
| author | Andreas Schneider <asn@samba.org> | 2016-10-20 10:37:18 +0200 |
|---|---|---|
| committer | Michael Adam <obnox@samba.org> | 2016-10-20 11:21:59 +0200 |
| commit | d8cf3b0ca8ce24aaf19e4692882dadffa921f763 (patch) | |
| tree | 946df3b980157248a6fd68290352235c6f4673c9 /src | |
| parent | c989bbc9f6afaad9e4b26501d57d7acb1297d1cb (diff) | |
| download | socket_wrapper-d8cf3b0ca8ce24aaf19e4692882dadffa921f763.tar.gz socket_wrapper-d8cf3b0ca8ce24aaf19e4692882dadffa921f763.tar.xz socket_wrapper-d8cf3b0ca8ce24aaf19e4692882dadffa921f763.zip | |
swrap: Handle threads that fork
Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Michael Adam <obnox@samba.org>
Diffstat (limited to 'src')
| -rw-r--r-- | src/socket_wrapper.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/src/socket_wrapper.c b/src/socket_wrapper.c index 18c1626..6679d5c 100644 --- a/src/socket_wrapper.c +++ b/src/socket_wrapper.c @@ -168,6 +168,13 @@ enum swrap_dbglvl_e { pthread_mutex_unlock(&(m ## _mutex)); \ } while(0) +/* Add new global locks here please */ +# define SWRAP_LOCK_ALL \ + SWRAP_LOCK(libc_symbol_binding); \ + +# define SWRAP_UNLOCK_ALL \ + SWRAP_UNLOCK(libc_symbol_binding); \ + #define SWRAP_DLIST_ADD(list,item) do { \ if (!(list)) { \ @@ -327,6 +334,8 @@ static pthread_mutex_t libc_symbol_binding_mutex = PTHREAD_MUTEX_INITIALIZER; /* Function prototypes */ bool socket_wrapper_enabled(void); + +void swrap_constructor(void) CONSTRUCTOR_ATTRIBUTE; void swrap_destructor(void) DESTRUCTOR_ATTRIBUTE; #ifdef NDEBUG @@ -5588,6 +5597,36 @@ int pledge(const char *promises, const char *paths[]) } #endif /* HAVE_PLEDGE */ +static void swrap_thread_prepare(void) +{ + SWRAP_LOCK_ALL; +} + +static void swrap_thread_parent(void) +{ + SWRAP_UNLOCK_ALL; +} + +static void swrap_thread_child(void) +{ + SWRAP_UNLOCK_ALL; +} + +/**************************** + * CONSTRUCTOR + ***************************/ +void swrap_constructor(void) +{ + /* + * If we hold a lock and the application forks, then the child + * is not able to unlock the mutex and we are in a deadlock. + * This should prevent such deadlocks. + */ + pthread_atfork(&swrap_thread_prepare, + &swrap_thread_parent, + &swrap_thread_child); +} + /**************************** * DESTRUCTOR ***************************/ @@ -5600,6 +5639,8 @@ void swrap_destructor(void) { struct socket_info_fd *s = socket_fds; + SWRAP_LOCK_ALL; + while (s != NULL) { swrap_close(s->fd); s = socket_fds; @@ -5613,4 +5654,6 @@ void swrap_destructor(void) if (swrap.libc.socket_handle) { dlclose(swrap.libc.socket_handle); } + + SWRAP_UNLOCK_ALL; } |